Control device for varying the speed of parachutes during the descent



G. LISI Feb. 22, 1944.

CONTROL DEVICE FOR VARYING THE SPEED OF PARACHUTES DURING THE DE FiledSept. 16, 1940 nae/28% 0417a see 0%: Lisa .9

' flor'neg parallel 4 limits a dome 2, whose size is such as to allow,when excluded the braking action of the skirt I, a very high descentspeed. On the line 4 there is fixed an internal rope system it connectedinto a suspension and traction member, comprising, for instance, thering I, the inextensible rope 8 andthe ring or pulley 9. A control rope10 secured to the suspension member ll of the external rope system I2passes through the ring or pulley 9 and returns downwards so as to bereached by the hand of the man suspended in 15 to the suspension memberH.

The external rope system 12 in the present case is provided withconnecting points l3 for rope groups 12, each of said points I3 isunited to the member H by means of inextensible cords I4.

The device functions as follows: In the descent at a low speed, the cordIn is slackened, the weight I5 gravitates only on the suspension memberH and the whole surface of the skirt l and calotte 2 constitutes theactive surface of the parachute. When an increase of speed is wanted, atraction is exercised on the free part of the cord [0, thus thesuspension member 9 approaching the suspension member ll, consequentlyby distribution in a variable proportion the load l5 between theexternal rope system l2 and the internal rope system 8, which whenlittle by little the members 9 and H are approaching to one another,bears a part always greater than the load l5 till this load iscompletely supported when the whole is trimmed in the position shown inFig. 2, this constituting the high speed trim.

Should a reduction of speed be wanted, it is suflicient to diminish thetraction exercised with the hands on the cord I leaving more or less theskirt I to come into action.

As already remarked, when beginning the application of the traction onthe rope H), the parachute formed by the skirt l and the upper dome 2being thus lightly deformed, the speed instead of increasing, decreasesat the beginning and descends below the value assumed when the wholeload is supported by the external rope system I2.

In Fig. 3, where the parts corresponding to those of Figures 1 and 2 areindicated with the same reference numbers, the inextensible cords I 4are replaced by rubber cords l6 making the suspension resilient andautomatically regulated the speed; when the cord I0 is completelyslackened and the suspension members 9 and II are connected by theinextensible rope I! illustrated in Fig. 3. This type of parachutecombines the advantages described in the application No. 340,196 alreadyfiled, and those according to the present invention.

In Fig. 4 there is illustrated a particular form of realisation of thesuspension member 3 of the internal rope system. The member 9 issubstantially of an ovoidal form and through its external groove therepasses the rope 8 bent on itself and fixed by a binding l9. Inside theovoid 9 there is mounted a pulley i8 around which there passes thecontrol cold ID. By conveniently choosing the dimensions and playsbetween the cord l0, pulley I8 and ovoid 9, a perfect functioning of thedevice is secured.

Thepresent invention has been illustrated and described in a preferredform ofrealisation, but it is understood that constructive changes maybe practically introduced therein without surpassing the limits ofprotection of the present industrial patent.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

A parachute comprising a canopy, a skirt portion on said canopy, primarysuspension cords extending from the outer periphery of said skirtportion, secondary suspension cords extending from the outer peripheryof said canopy, a suspension member secured to said primary suspensioncords, a block secured to said secondary suspension cords with securingmeans in the form of a cord attached to said secondary suspension cordsand extending about the periphery of said block, a pulley mountedcentrally upon a horizontal axis in said block, and a control ropesecured to said suspension member and passing over said pulley, wherebythe operator can trans- .fer the Weight carried by the suspension memberfrom said primary suspension cords to said sec ondary suspension cordsso that the entire weight may be supported by said canopy with theresult that the rate of descent of the parachute is controlled.

GIUSEPPE LISI.

